You were *very* unlucky.
I've had two 405s for a total of about 5 years, and the only none-trivial faults I ever had were a leaky heater-matrix on the Mk2 (sorted under warranty), and the Mk1 occasionaly jumped out of 3rd gear when you lifted off. Both were getting on for 100k when I got rid of em, and the interiors were still immaculate. Do you wear studded clothes or something ?